In general, rotary tools and oscillating tools are light-weight, handheld power tools capable of being equipped with a variety of tool accessories and attachments, such as cutting blades, sanding discs, grinding tools, and many others. These types of tools, referred to hereinafter as power tools, typically include a generally cylindrically-shaped main body that serves as an enclosure for an electric motor as well as a hand grip for the tool. The electric motor is operably coupled to a drive member, referred to herein as a tool holder, that extends from a portion of the main body of the power tool. The electric motor is configured to rotate and/or longitudinally oscillate the tool holder at relatively high frequencies. The tool holder in turn is configured to secure different accessory tools so that as the tool holder is driven to move by the electric motor, an accessory tool secured to the holder is driven to perform work on a workpiece.
The accessory tools are typically secured in the tool holder by a clamping mechanism to prevent slipping of the tool and loss of power to the tool. The load applied to the clamping mechanism must be amplified in order to generate enough clamping load to the accessory to secure the tool in the tool holder. Typically this load amplification is achieved through the use of wrenches that allow the user to apply torque to generate a large amount of clamping force that clamps the tool in the tool holder. In some instances, however, the wrench can become separated from the tool or the user may be unable to generate sufficient clamping force even with the wrench. Furthermore, wrench clamping systems increase the size of the tool holder, as the tool holder must have an interface to engage the wrench. It would be beneficial, therefore, to provide improvements to tool holders that simplify clamping of the tool therein.